Wednesday, March 23, 2016

After savanna burn: good time to see old-growth forest structure

On Monday March 21 2016 we had a great burn of the oak savannas at Pleasant Valley Conservancy. The next day Kathie and I returned to assess the burn coverage and take pictures. It turned out to be an excellent time to see the forest structure in all its simplicity. Before leaf out of trees and shrubs, before forbs and grass growth. The black forest floor provides an excellent contrast with the trees.

How is an old-growth forest characterized? These are the keys, as taken from the forestry literature:

Mix of young and old trees

Many fallen and decaying trees

Light gaps

Trees in various stages of decline

Wide diversity of plant species

No or only minimal past disturbance from logging or agriculture

Coarse woody debris on the forest floor

According to the experts, in Eastern United States it takes 150 years or longer to reach old-growth character. According to our minimal evidence, our white savannas are between 150-200 years old and many of our bur oaks are older than 200 years.